One of the best things I have found for troubled eaters is newspaper. Sounds strange but ball up pieces of newspaper and cram the tub full (I mean FULL) of newspaper. It wont even look like the animal will have room to get out of his hide but he will. Pack it to the top then wait about a week, offer food (with paper still in tub) This has worked for me with several trouble feeders. I was told of this method by a big breeder a few years ago.
And if it don't work, you're only out $.50.